Conventional television monitoring systems fall into two general catagories: those utilizing hardwired connections between the cameras and a central location and those utilizing radio-link communications. The hardwired type of systems are generally confined to studio environments or other fixed locations in which it is convenient to interconnect the individual television cameras via cables extending between the cameras and a central console that includes monitors and personnel to effect coordinated operation of the system. In studio applications, the individual cameras are typically manned by a cameraman who adjusts the camera lens or otherwise effects optical control in response to audio instructions from the central location. At the central location, the output signals of the cameras may be selected for subsequent transmission. In those systems in which the remote television cameras are coupled to a central location via radio transmission links, the cameras are also typically controlled at the location by a cameraman who effects pointing control and control over the optics of the system, under control of personnel at a central location. Both types of systems suffer from the disadvantage that personnel must be located at the remote station to effect operation of the camera. In other types of television monitoring systems, a plurality of television cameras are located at fixed positions in a specific facility, for example, the security perimeter of an industrial installation, with these cameras hardwired to a central location which includes monitors to permit central station personnel to observe the secured area. Typically, the fixed cameras do not have optical control and are designed merely to scan a predetermined area and provide the television image information to the central location.
It is a broad overall object of the present invention to provide a television monitoring system to permit observation of various locations by plural cameras with simple and reliable selection and control of the cameras from a central location.
It is another object of the present invention to provide a wide area television monitoring system in which selection and control of a plurality of remotely located cameras can be effected from a central location in which the central location and the remote location are coupled through a radio communication link.
It is still another object of the present invention to provide a wide area television monitoring system in which the central station is coupled to a remotely located station by a radio communications link whereby one or both of the central and/or remote locations may be mobile relative to the other.
It is still another object of the present invention to provide a wide area television monitoring system that includes a plurality of television cameras that may be controlled either through the central station or the remote station.
It is still another object of the present invention to provide a wide area television monitoring system that includes a central station and a remote station having a plurality of television cameras that are selected, enabled, and controlled from either the central or the remote station and in which the remote station includes means by which the remote station simultaneously auto-enables and enables the central station.
In accordance with these objects, and others, a television monitoring system in accordance with the present invention includes a central station coupled by a radio communications link to a remote station that includes a plurality of audio/video cameras connected thereto. The central station includes a control signal generator/encoder means for generating dual-tone camera select signals and single-tone camera control signals and a transmitter for transmitting the tone encoded control signals to the remote station. A control-signal receiver at the remote station receives the so-transmitted camera select and camera control tone-encoded signals and provides these signals to a decoder which effects decoding and selection and control of a selected camera. An audio/video signal transmitter is provided at the remote station to transmit the audio/video signal provided from the selected camera to an audio/video receiver located at the central station to permit monitoring and recording of the signal from the so-selected camera. In addition, means are provided at the remote station to permit the remote station to substantially simultaneously auto-enable and enable the central station in response to a predetermined occurence or event. In accordance with another feature of the present invention, a camera identification generator is provided to superimpose the camera identification information and, if preferred, time-of-day information on the camera video output signal to positively verify the identity of the selected camera at the central location.
The monitoring system advantageously permits flexible control over a large number of cameras and convenient camera selection and control from the central location and includes the feature whereby the remote station may auto-enable itself and an otherwise dormant central station. Video time-tag and camera identification information is superimposed upon the selected camera's video signal to permit convenient verification of the selected camera identity at the initiating remote location.
The system may be used in a wide number of applications including, for example, applications in which the central station is mobile relative to a fixed remote station (that is, a plurality of fixed cameras at the perimeter of an industrial installation with the central station mounted in a mobile vehicle for monitoring purposes); applications in which the remote station is mobile relative to the fixed station (for example, a plurality of cameras located on or in different sections of an aircraft for selection and control thereover by a land-fixed central station); and those applications in which both the central and remote station are mobile (for example, a plurality of cameras located on an aircraft for selection and control thereover by a central station on another aircraft).